<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>自适应正方形</title>
    <style>
        .one{
            width:20vh;
            height:20vh;
            background: deepskyblue;
        }
        .two{
            width: 10%;
            padding-bottom: 10%;
            height: 0;  /*防止内容撑开多余的高度*/
            background: red;
        }
    </style>
</head>
<body>
    <div class="one">vh  vw</div>
    <hr>
    <div class="two">围护结构发送到围护结构发送到围护结构发送到围护结构发送到围护结构发送到围护结构发送到围护结构发送到围护结构发送到</div>
</body>
</html>
